Steroid-resistant idiopathic nephrotic syndrome in children: long-term follow-up and risk factors for end-stage renal disease.

INTRODUTION: Steroid resistant idiopathic nephrotic syndrome (SRINS) in children is one of the leading causes of progression to chronic kidney disease stage V (CKD V)/end stage renal disease (ESRD). OBJECTIVE: The aim of this retrospective study is to evaluate the efficacy of immunosuppressive drugs (IS) and to identify risk factors for progression to ESRD in this population. METHODS: Clinical and biochemical variables at presentation, early or late steroid resistance, histological pattern and response to cyclosporine A (CsA) and cyclophosfamide (CP) were reviewed in 136 children with SRINS. The analyzed outcome was the progression to ESRD. Univariate as well as multivariate Cox-regression analysis were performed. RESULTS: Median age at onset was 5.54 years (0.67-17.22) and median follow up time was 6.1 years (0.25-30.83). Early steroid-resistance was observed in 114 patients and late resistance in 22. Resistance to CP and CsA was 62.9% and 35% respectively. At last follow-up 57 patients reached ESRD. The renal survival rate was 71.5%, 58.4%, 55.3%, 35.6% and 28.5% at 5, 10, 15, 20 and 25 years respectively. Univariate analysis demonstrated that older age at onset, early steroid-resistance, hematuria, hypertension, focal segmental glomerulosclerosis (FSGS), and resistance to IS were risk factors for ESRD. The Cox proportional-hazards regression identified CsAresistance and FSGS as the only predictors for ESRD. CONCLUSION: Our findings showed that CsA-resistance and FSGS were risk factors for ESRD.

Steroid-resistant idiopathic nephrotic syndrome in children: long-term follow-up and risk factors for end-stage renal disease / Síndrome nefrótica idiopática córtico-resistente na criança: evolução e fatores de risco para falência renal crônica

INTRODUTION: Steroid resistant idiopathic nephrotic syndrome (SRINS) in children is one of the leading causes of progression to chronic kidney disease stage V (CKD V)/end stage renal disease (ESRD). OBJECTIVE: The aim of this retrospective study is to evaluate the efficacy of immunosuppressive drugs (IS) and to identify risk factors for progression to ESRD in this population. METHODS: Clinical and biochemical variables at presentation, early or late steroid resistance, histological pattern and response to cyclosporine A (CsA) and cyclophosfamide (CP) were reviewed in 136 children with SRINS. The analyzed outcome was the progression to ESRD. Univariate as well as multivariate Cox-regression analysis were performed. RESULTS: Median age at onset was 5.54 years (0.67-17.22) and median follow up time was 6.1 years (0.25-30.83). Early steroid-resistance was observed in 114 patients and late resistance in 22. Resistance to CP and CsA was 62.9% and 35% respectively. At last follow-up 57 patients reached ESRD. The renal survival rate was 71.5%, 58.4%, 55.3%, 35.6% and 28.5% at 5, 10, 15, 20 and 25 years respectively. Univariate analysis demonstrated that older age at onset, early steroid-resistance, hematuria, hypertension, focal segmental glomerulosclerosis (FSGS), and resistance to IS were risk factors for ESRD. The Cox proportional-hazards regression identified CsAresistance and FSGS as the only predictors for ESRD. CONCLUSION: Our findings showed that CsA-resistance and FSGS were risk factors for ESRD.

INTRODUÇÃO: A síndrome nefrótica idiopática córtico-resistente (SNICR) é uma das principais causas de falência renal crônica (FRC)/doença renal crônica estadio V (DRC V) em crianças. Objetivo: Avaliar a resposta aos imunossupressores e identificar fatores de risco para a FRC. MÉTODOS: Variáveis clínicas e bioquímicas na apresentação, resistência inicial ou tardia aos esteroides, lesão histológica e resposta à ciclosporina A (CsA) e à ciclofosfamida (CF) foram analisados retrospectivamente em 136 crianças com SNICR. O desfecho analisado foi a progressão para FRC e os métodos utilizados foram a análise univariada e a regressão multivariada de Cox. RESULTADOS: A idade mediana do início da doença foi de 5,54 anos (0,67-17,22) e o tempo mediano de seguimento foi de 6,1 anos (0,25-30,83). Resistência inicial aos esteroides ocorreu em 114 pacientes e tardia em 22. Resistência à CF e à CsA ocorreu em 62,9% e 35% dos pacientes, respectivamente. FRC ocorreu em 57 pacientes. A sobrevida renal foi de 71,5%, 58,4%, 55,3%, 35,6% e 28,5% aos 5, 10, 15, 20 e 25 anos, respectivamente. A análise univariada demonstrou que a idade maior ao início da doença, resistência inicial aos esteroides, hematúria, hipertensão, glomeruloesclerose segmentar e focal (GESF) e resistência aos imunossupressores foram fatores de risco para FRC. A regressão de Cox identificou a resistência à CsA e a GESF como os únicos fatores preditores para FRC. CONCLUSÃO: Nossos achados mostraram que a resistência à ciclosporina e a presença de GESF foram fatores de risco para a progressão para DRCV.

Long-term follow-up after cyclophosphamide therapy in steroid-dependent nephrotic syndrome.

Cyclophosphamide (CP) has been used for over 40 years in patients with steroid-sensitive nephrotic syndrome (SSNS) presenting frequent relapses or steroid dependence (SD). We evaluated retrospectively and tried to identify parameters possibly associated with a prolonged and sustained remission (PSR+) ≥5 years in 108 children with steroid-dependent nephrotic syndrome (SDNS) treated with oral CP. Patients had a follow-up time ≥5 years and were divided into two groups according to achievement of PSR (+ and -). Gender, histological injury, cumulative doses of CP, age of onset of illness, and start of treatment and prednisone dose on the occasion of relapse were analyzed. The overall cumulative sustained remission for 5 and 10 years was 25 and 21.6%, respectively. The only factor that influenced a PSR was the degree of SD: the group PSR+ relapsed at prednisone dose of 0.96 ± 0.51 mg/kg vs. 1.29 ± 0.59 mg/kg in group PSR- (p = 0.01). Also, patients who relapsed in the presence of prednisone doses ≤1.4 mg/kg showed a cumulative sustained remission of 43, 35, and 32.7% at 2, 5, and 10 years, respectively, versus 22.5, 12.5, and 5% in those with prednisone >1.4 mg/kg (p = 0.001). Our findings suggest that patients with SDNS who relapse on prednisone dose >1.4 mg/kg are especially prone to an unfavorable response to CP use.